Patent US 5,206,930

A method of compliance control of an industrial manipulator having a high position rigidity is achieved by integrating the motion equation to obtain a position displaced by a detected external force, calculating the trajectory of a position in a joint coordinate system with inverse kinematics, differentiating the calculated trajectory to obtain the trajectories of velocity and acceleration, and performing position control using these latter trajectories. The result is allowance of the compliance to be specified in any desired Cartesian coordinate system in the form of second-order perturbations including stiffness and damping. Moreover, the specified compliance can be realized with separation of the compliance specifications from the system feedback gain.